An historical account of the `WearComp' and `WearCam' inventions
developed for applications
in `Personal Imaging'

Abstract:

We are entering a pivotal
era in which we will become inextricably
intertwined with computational technology that will become part of
our everyday lives in a much more immediate and intimate way
than in the past.
The recent explosion of interest in so-called ``wearable computers''
is indicative of this general trend.
The purpose of this paper is to provide an historical account of
my wearable computer effort, from the 1970s
(WearComp0) to present (WearComp7),
with emphasis on a particular variation
whose origins were in imaging applications.
This application, known as `personal imaging', originated as a
computerized photographer's assistant which
I developed for what many regarded
as an obscure photographic technique. However,
it later evolved into a more diverse apparatus and methodology,
combining machine vision and computer graphics,
in a wearable tetherless apparatus, useful in day-to-day living.
Personal imaging, at the intersection of art, science, and technology,
has given rise to a new outlook on photography, videography,
augmented reality, and `mediated reality', as well as new theories of
human perception and human-machine interaction.
My current personal imaging apparatus, based on a camera and display
built within an ordinary pair of sunglasses, together with a
powerful multimedia computer built into ordinary clothing, points to a new
possibility for the mass-market.

In this paper, I describe a particular physical arrangement of a computer
system, which I call `WearComp'.
It has the following characteristics[1]

eudaemonic criterion:
The computational apparatus is situated in a manner
that makes it part of what the highly-mobile user considers himself or
herself,
and in a manner that others also regard as part of the user.
Thus it is not tethered to an AC outlet, desktop, or the like,
nor is it a separate object, or collection of separate objects being
carried by the user.

It is often sufficient that the interface (input and output)
alone satisfy this criterion so that some of the computational
resources can be remotely located if desired.

existential criterion:
The computational capability
is controllable by the user. This control need not
require conscious thought or effort,
but the locus of control must be such that
it is within the user's domain. In this way it may behave as an
extension of the user's mind and body as opposed to merely
being a remote monitoring or recording device or the like.

ephemeral criterion:
Time in processing queue (CPU) and I/O queue (user) is negligible.
In Today's computing framework, this condition can be
made even stronger:
interactional and operational delays are nonexistant,
or very small, as
the computational apparatus is
constant in both its operation and its potential for
interaction with the user.

Operational constancy:
It is always active while worn.
It may have sleep modes, but it always has the ability to
turn itself on and, for example, take notice of its environment
by virtue of some sensing apparatus (e.g. it may ``sleep'',
but it should never ``die'').

Interactional constancy:
One or more output channels (e.g. screen/viewfinder) are known
(e.g. visible) to the user at all times,
not just when the computer is being interacted with in a
deliberate manner.
In this way, context switching time to mentally engage with the
apparatus is near zero.

Two early wearable computers were built
independently. During the 1970s, I
built a system (Fig 1(a-c)) for experimental
photographic applications, unaware of wearable
computers (Fig 1(d))
that were being built by a group of west-coast physicists,
known as the Eudaemons[4].

Figure 1:
Two early wearable computers
developed in the 1970s.
(a) A ``photographer's assistant''
system comprising my late 1970s
wearable computer (pictured here with 1980 display).
I integrated the computer into a welded-steel frame worn on my
shoulders (note belt around my waist which directed much of the
weight onto my hips). Power converter hung over one shoulder.
Antennae (originally 3, later reduced to 2),
operating at different frequencies,
allowed simultaneous transmission and reception of computer data,
voice, or video. This system allowed for complete interaction
while walking around doing other things.
(b) Close up of the uppermost end of the lightpaintbrush
handle, showing the end that's held in my right hand.
The collection of six
spring-lever switches, one for each finger and two for thumb,
permits input of data, as well as control of the lightpainting
programs.
(c) Close up of my 1980 display.
(d) The Eudaemons' shoe-based computer which used a vibrotactile
display (described in[5])
as its sole output modality.
Thanks to Doyne Farmer for loan of shoe computer from which I took
this picture.

It is interesting to contrast these two early wearable computing
efforts.

In the late 1970s, the Eudaemons designed and built various wearable
computers for purposes of assisting a roulette player predict where
the ball would land. Rather than attempting to predict the exact
number on which the ball would land, they divided the wheel into eight
octants, and attempted to predict which octant the ball would land in.
It was not necessary to predict this outcome with high accuracy --
it was sufficient to occasionally (with probability
only slightly better than pure chance) know which octant the ball
would land in. In this manner, the apparatus
was successful in providing a small
but sufficient increase in betting odds, for purposes of
winning money in the game of
roulette.

In various implementations, two players would collaborate: one would
watch the ball and click a footswitch each time it passed, while the
other would receive this timing information wirelessly from
the second person who was to place the bet. The
shoe-based computer (Fig 1(d)) using a physical
model of the roulette table, based on nonlinear dynamics,
would indicate one
of nine possibilities: a particular octant, or a ninth suggestion
that no bet be placed. One of these nine possibilities was presented
to the bottom of the foot in the form of vibrations of three solenoids
which were each programmed to vibrate at one of three possible vibration
rates (slow, medium, or fast). The person placing the bets would
need to memorize the numerical values in each octant of the roulette
table, as well as learn the nine different vibration patterns that
the three solenoids could produce.

During the 1970s,
I envisioned, designed, and built the first WearComp
(called WearComp0, which evolved into WearComp1)
to function as an experimental ``photographer's assistant''
for a new imaging technique.
The goal of this technique
was to characterize the manner
in which scenes or objects responded to light, through the process of
gathering differently exposed/illuminated pictures.
The procedure resulted in a richer scene description,
which allowed
more expressive/artistic images to be rendered.
This technique was recently
described in[6][7].
(See Fig 2.)

Figure:
(a) Image from one of my recent exhibitions,
which I generated from data taken
using my personal imaging system.
The unique capabilities of a completely tetherless
wearable {computer,imaging,graphics} system
facilitate a new
expressive capability with images that could not be created by
any other means. The images transcend the boundary between
photography, painting, and computer graphics.
(b,c) Data sets are collected based on response to various
forms of illumination.
(b) Personal imaging computer in use with
40000 Joule flash lamp operating at 4000V DC with 24kV
trigger.
(c) With 2400 Joule
flash lamp operating at 480V with 6kV trigger.

The photographer's assistant
system comprised two portions,
a WearComp with light sources (as peripherals),
and a base-station with imaging apparatus. The imaging technique,
referred to as `lightspace',
involved determining the response of a typically static scene or object
to various forms of illumination, and recording the
response measurements (originally in analog form on photographic emulsion)
at the base station.

This project evolved into a system
called WearComp2, which
also had some degree of graphics capability,
digital sound recording and playback capability,
and music synthesis capability.

I built WearComp2 (a 6502-based wearable
computer system completed in 1981)
into a metal frame pack (welded-steel pipe construction), and
powered it by lead-acid batteries.
The power distribution
system was constructed to also
provide power for
radio communications, both inbound and outbound,
as well as for electronic flash (900 volts).
I achieved power inversion
by a combination of astable multivibrators (manufactured by Oaks and Dormitzer),
and a matched pair of germanium
power transistors salvaged from the inverter section of a tube-type
automotive taxicab
radio.
At this time, a widespread practical use for battery operated computers had
not yet been envisioned, and therefore there were no such ``portable''
computers available. The first portables (such as the Osborne computer,
a unit about the size of a large toolbox) were yet to appear in the
early 1980s.

Input comprised a collection of
pushbutton switches (typically located on the handle of one of my
specialized light sources, each one having its own ``keyboard'')
which could be used to enter program instructions, as
well as to take down notes (e.g. details about a particular photographic
situation).

In addition to simple control of imaging commands, I also desired
some automated functionality. For example, I wanted the
base station to automatically know my wherabouts, so that
additional information about each exposure could be kept for later use,
as well as for immediate use.

Ideally, a tape measure would be used
to measure the location on the ground where I was standing,
and the height of the flash lamp above the ground, and instruments would
be used to determine its azimuth and elevation (direction of aim).
However, due to time constraints, it was more typical that I would
count the distance in `paces' (number of footsteps), and report these numbers
verbally (using two-way radio)
back to my assistant at the base station taking notes. This
procedure itself, because it required the attention of an
assistant, was
undesirable, so I included a pedometer in my shoes to
automate this counting process (initially on an electro-mechanical
counter manufactured
by Veeder Root, and later on the wearable computer with the Veeder Root
counter as a backup to occasionally verify my count).
Due to count errors (in both the computer and backup), I also
experimented with the use of ceramic phono cartridges, piezo elements,
and resistive elements, using some hysteresis in the counting circuitry.

Experiments in replacing the pedometers with radiolocation were not
particularly successful (this was, of course, long before the days
of the Global Positioning System (GPS)).
One approach that was somewhat successful
was the use of radar for estimating short distances and rough velocities
with respect to the ground. For this purpose, I
designed and built a small wearable radar system.
This invention proved more useful later
for other projects, such as a
safety device to warn if someone might be sneaking up from behind,
and later as an assistant to the visually impaired who could use it to
``feel'' objects ``pressing'' against them before
contact.
Some years later, in the late 1980s,
I presented wearable radar to the Canadian National
Institute for the Blind, but it was never widely adopted,
mainly due to the poor performance
arising from the limited capabilities of my wearable computers of
this era. With Today's more sophisticated
wearable computers, capable of implementing variations of the
chirplet transform[8]
in realtime (to obtain radar
acceleration signatures of objects in the wearer's
vicinity), I hope to
revive my ``BlindVision'' project of the 1980s[9].

I designed the analog to digital and digital to analog converters
for WearComp2 from resistive
networks (and later, in the early 1980s,
by using more expensive Analog Devices chips).
In both cases, I designed these
with sufficient throughput for radar, voice, and music.

Music synthesis capability was envisioned as
a means of providing information (such as light levels,
exposure settings, etc.) in the form of sound, but also evolved into
a portable self-entertainment system (a predecessor of the SONY Walkman).

Voice digitization and playback capability
in WearComp was included for experimental
purposes, with the ultimate objective of taking down voicenotes
pertaining to exposure information and the like.
Unfortunately, the system only had 4k of RAM (later expanded to 48k),
so the voice digitization capability was of little real practical use
in the field. However, because I built the analog to digital and digital to
analog converters as separate units, facilitating
the possibility of full-duplex audio, I used this capability
for simple voice processing, such as
reverberation, and the like.
Computer programs and data (and later commercial software
including an assembler) were stored on audio cassettes.
In 1981, a battery powered
audio cassette recorder served as the only non-volatile digital storage
medium for the wearable computer system.
The cassette drive also proved useful for storage of voicenotes in analog
form. (Later an 8 inch floppy drive, followed by a 5.25 inch floppy
drive, were incorporated.)

Because of the limited technology of the era, the system was ``hybrid''
(part digital and part analog) in many regards. In addition to the audio
cassette recorder (used to record analog voice as well as digital programs
and data), the communications channel was also hybrid.

Communications comprised a total of four voice
transceivers.
On the body, was a radio transmitting
constantly on one channel,
and another radio receiving constantly on
a different channel.
At the base station, the situation was the same but with the channels reversed.

The modems I constructed, from simple
free-running (non coherent) audio frequency
oscillators and corresponding filters,
operated at a data rate of approximately 45 bits per second.
(Another early communication attempt averaged 1500bps but was
somewhat unreliable.)

The hybrid communications channel was capable of sending and receiving
full-duplex voice (e.g. to talk to an assistant at the base station)
or data (e.g. to control the imaging apparatus at the base station).
Video capability was also included in the system, but at a much higher
frequency (not going through the radio channel that was used for
voice and data). Video was an important aspect of the system, as
I desired to see what the scene looked like from the
perspective of the base station.

Less important, but still useful,
was the desire that, during times at which there was an assistant at
the base station, the assistant be able to experience my
point of view (for example, to see how well the flashlamp provided
coverage of a particular object, and to observe the nature of this
illumination). I developed
a device, known as the `aremac' (camera spelled
backwards), comprising an electronic flash which had a viewfinder
to preview its field of coverage.
The situation in which I could look through the imaging apparatus
at the base station while the assistant at the base station
could look through my
``eyes'' (aremac) was found to be useful as a communications aid,
especially when combined with full-duplex audio communication.
I referred to this mode of operation as `seeing eye-to-eye'.

My wearable computer efforts of the 1970s
were a success in some ways, and a failure in others.
The success was in demonstrating the functionality of an early
prototype of wearable computer
system, and in formulating a practical application domain
for wearable computing.
However, there were many technical failures. In particular,
the bulky nature of the apparatus rendered it often more of a
photographer's burden than a photographer's assistant.
Furthermore, the reliability problems associated with so many different
system components were particularly troublesome, given the nature
of typical usage patterns: walking around on rough terrain where wiring
and the like would be shaken or pulled loose.
Interconnections between components
were found to be one of the major hurdles.

However, much was learned from these early efforts, and I decided that
a new generation of wearable computers would be necessary if the apparatus
were to be of real benefit. In particular, I decided that the apparatus
needed to be more like clothing than like a backpack. To this end, I
attempted spreading components somewhat uniformly
over ordinary clothing (Fig 3).
This effort succeeded in providing a truly helpful photographer's
assistant, which, later, was to help me win ``Best Color Entry'',
two years in a row (1986 and 1987),
in the National Fuji Film Photography Competition.

Figure 3:
Generation-2 WearComps were characterized by
distributed components, with wires sewn into clothing.
(a) In my dressing room, testing flash sync
with the waist-worn television set as display medium.
Note the array of pushbutton switches on
the handle of the electronic flash which comprise a
``keyboard'' (data-entry device) of sorts.
Here I am partially dressed (a black jacket
with the remainder of the communications antennas sewn into
it has yet to be put on). Note the absence of the backpack,
which has been replaced by a more distributed notion of
wearable computing.
(b) Completely dressed, in the field. Note
my newer generation-2 flash system (homogeneous
array of 8 small lightweight electronic flashlamps)
in keeping with the
distributed philosophy of generation-2 WearComp.
(Figure courtesy of Campus Canada, 1986 and
Kent Nickerson, 1985)

Generation-2 WearComp (I
referred to Gen-2 and Gen-3 as `smart clothing')
was characterized by a far greater degree of comfort, with a
tradeoff in setup time (e.g. the increased comfort was attained
at the expense of taking longer to get into and out of the apparatus).
Typical `smart clothing' comprised special pants, a special vest,
and special jacket, which I connected together, such that much time
and care were required to assemble everything into a working outfit.
A side-effect of generation-2 WearComp, was the fact that
it was more inextricably intertwined with the wearer.
For example, instead of running
wires from the sensors in the shoes up to the backpack,
the shoes could simply be plugged
into special pants that had a wiring harness and wiring already sewn in.
These pants were then plugged into the compute vest, which was in turn
plugged into the radio jacket, establishing a wireless connection
from the shoes to the base station, without a tangled mess of wires
as was characteristic of my generation-1 WearComp.
Later, other experiments were facilitated by the clothing-based computing
framework (for example, electrical stimulation of the
muscles, attempts at monitoring the heart and other physiological parameters,
etc.)
which it was hoped might add a new dimension to WearComp.

Because of the more involved dressing and undressing procedures, I
built a special dressing area, comprising rows of hangers to hang up the
clothing, and floor-to-ceiling shelves (visible in the background
of Fig 3(a). Much of my generation-1 apparatus
remained, and my generation-2 components were made in such a way that they
continued to be compatible with generation-1 components.
For example, NTSC as well as certain variations of NTSC
remained the dominant computer display format.
In Fig 3(a), a mixture of generation-1 and generation-2
components are being tested. Note the waist-mounted display,
which was found to be more comfortable than the display of
Fig 1(a). In particular, the older generation of
display was very uncomfortable due to its front-heavy nature, and its
large moment of inertia.

The new generation of display was found to be much more comfortable
(e.g. could be worn for several hours at a time), but it lacked a
certain kind of interactional constancy that can best be described as
cyborgian[10]. Although it was always on during operation,
the fact that light from the display was not always entering the eye
was found to detract from its utility in certain applications.
Use of the waist-mounted television was somewhat reminiscent of
a camera with a waist-level viewfinder (e.g. the old Brownie Hawkeye,
the Rolleiflex, or the more modern Hasselblad).

With the advent of the consumer video camera,
the consumer electronics industry created
a newer generation of miniature CRTs for camera viewfinders.
These were particularly suitable for eyeglass-based wearable
computing displays[11], allowing the waist-mounted
television display to be abandoned.

Ivan Sutherland described a head-mounted display with half-silvered
mirrors so that the wearer could see a virtual world superimposed
on reality [12].
Sutherland's work, as well as more recent
work by others [13]
was characterized by its tethered nature.
Because the wearer was tethered to a
workstation which was generally powered from an AC outlet, the
apparatus was confined to a lab or other fixed location.
Another reason for augmented reality systems being confined to some
limited space was/is the use of 2-part trackers that require that
the user, wearing one part, be near the other part, which is typically
heavy and often carefully positioned relative to surrounding
objects[13].

Generation-1 and 2 WearComp was typically
characterized by a display
over only one eye. Early wearable displays (such as the one in
Fig 1(c)) were constructed with a CRT above the eye,
aimed down, and then a mirror was used, at a 45-degree angle, to
direct the light through a lens, into the eye. In some cases, the
lens was placed between the mirror and the CRT, and a partially silvered
mirror was used. Regardless of whether a see-through display or
a display that blocked one eye completely was used, the perceptual effect
was to see the computer screen as though it was overlaid on reality.
This resulted in an augmented reality experience, but differed from
previous work by others, in the sense that I
was free to roam about untethered, while engaged in this experience.

Much more recently, Reflection Technology introduced
a display called the ``Private Eye'',
making it possible to put together a wearable computer from off-the-shelf
board-level components, giving rise to a number of independent
wearable computing research efforts
appearing simultaneously
in the early 1990s[14].
Thad Starner, one of those who began wearable computing work in the
1990s,
refer to the experience of seeing text on a non-see-through display
as a form of augmented reality[15],
because, even though the text completely blocks part of the vision
in one eye, there is an illusion of overlay on account
of the way the brain perceives input from both eyes as a combined image.

Unfortunately, the Private Eye-based wearable computers, unlike my
earlier video-based systems, were primarily text-based systems.
The Private Eye display consisted of a row of red LEDs that could be
switched on and off rapidly, and a vibrating mirror that would create
an apparent image, but this could not, of course, produce a
good continuous-tone greyscale image. Thus I did not
adopt this technology, but
instead, envisioned, designed, and built
the third-generation of WearComp
based on the notion that it should support personal imaging,
yet be at least as small and unobtrusive
as the generation of off-the-shelf solutions built around the Private Eye.

My current wearable computer/personal imaging systems
(See, for example, Fig 4)
are characterized by their almost
unobtrusive (visually undetected by a large number of people) nature.

Figure 4: Current state of the WearComp/WearCam
invention comprises a complete multimedia computer, with
cameras, microphones, and earphones, all built into
an ordinary pair of sunglasses except for some of the
electronics items sewn into the clothing.
This system is typical of generation-3 of my
WearComp project, and is suitable for wearing in
just about any situation (other than bathing or during
heavy rainfall). I've even fallen asleep with the unit on
from time to time.
With the system pictured here,
for fully-mediated reality environments,
I needed to close one eye, though I have built other similar
two-eyed units.
This rig is currently running the Linux 2.0 operating
system, with XFree86 (variant of X-windows), and has
a realtime bi-directional connection to the Internet.

The most recent WearComp prototype[16],
equipped with head-mounted display,
camera(s), and wireless communications,
enables computer-assisted forms of interaction in ordinary day-to-day
situations, such as while walking, shopping, or meeting people.

While the past generations have been very cumbersome and obtrusive,
current functionality has
``disappeared'' from view and been subsumed
into ordinary clothing and ordinary sunglasses.

In the early 1980s, I had already been experimenting with some
unobtrusive radio communications systems based on
conductive threads, as well as clothing-based computers,
such as a speech-controlled LED lightpaintbrush (Fig 5(d))
which I also wore to high-school dances, and the like, as a fashion
item.
Currently, I am trying to improve this approach to using clothing itself
as a connectivity medium.
I experimented with two approaches to making ``smart fabric'': additive
and subtractive. In additive, I start with ordinary cloth and sew
fine wires or conductive threads into the clothing.
I implemented the subtractive form using
conductive cloth, of which I have identified
four
kinds which I call BC1, IC1, BC2, IC2 (conductive one direction, and
conductive in both directions, either bare or insulated,
respectively). See Fig 5(a). Some of these have been used in
certain kinds of drapery for many years, the conductive members woven
in for appearance and stiffness, rather than electrical functionality.
Ordinary cloth I call C0 (conductors in zero directions).
Smart clothing may have
multiple layers, e.g. BC2 as RF shield, followed by
one of the following possibilities:

two BC1 layers with C0 to insulate them,

two IC1 layers oriented at right angles,

a single IC2 layer,

the first two being equivalent, while the last requiring additional
incisions to be made to disconnect unwanted extra connectivity in both
dimensions where insulation is removed with solvent.
Either of these three options allow components to be "wired"
together into something that's unobtrusive even to the new
see-through-clothing security
cameras
(I measured some BC2, and found it
to provide approximately 60dB of protection over a wide range of
frequencies).
Connections to `smart clothing' are shown in Fig 5(b,c).

Figure 5: An early smart clothing effort as possible future generation
of WearComp. (a) Four kinds of conductive fabric (see main text
of article for description). (b) Back of LED shirt showing
where one of the LEDs is soldered directly to type-BC1 fabric
(the joint has been strengthened with a blob of glue).
Note the absence of wires leading to or from the glue blob,
since the fabric itself acts as conductor.
Typically one layer of BC1
is put inside the shirt, while the other
is outside the shirt. Alternatively, either an undergarment is
used, or a spacer of type-C0 between the two layers.
(c) Three LEDs on type-BC1 fabric, bottom two lit, top one off.
(d) LED shirt driven by wearable computer. (C) 1985 by Steve Mann;
thanks to Renatta Bererra for assistance.

The compact unobtrusive nature of the apparatus, and the corresponding
ability for long-term wear, has led to a new genre of cinematography,
and the possibility of personal documentary exhibited in real-time.
Wearable Wireless Webcam (the author's Internet-connected
personal imaging workstation transmitting to an online gallery)
was one example of a long-term (two year)
personal documentary of day-to-day experience,
transmitted, for realtime consumption,
to a remote audience[16].

Mediated reality[18]
differs from augmented reality in the sense that not only
can visual material be ``added'' to augment
the real world experience, but reality may
also be diminished or otherwise altered if desired.
One example application,
the correction of visual deficiencies, was presented in[19].

In addition to further insights in human perception,
some new inventions arose out of this work. For example, the
``life through the screen'' experience, over a three-year period, caused
the author to visually evolve into a 2-D thought paradigm.
(Others have reported ``living in video-mediated reality''[20],
but only over short time-periods, perhaps due to the more cumbersome
nature of their apparatus, which also did not contain any computational
capability.)

``Life through the screen''
gave rise to a manner of pointing at objects
where the author's finger would be aligned with the object on the
screen, yet others who were watching the author
point at something (like an exit sign or surveillance
camera up in the air), would indicate that,
from their vantage, the author's finger appeared to be pointing
in another direction.

This ``life through the screen''[18]
resulted in some new observations,
among them, that the finger would make a useful pointing device
for a personal imaging system.
This pointing device, called the
fingermouse, was reported in [11]
and [15].

The motivation for homographic modeling
arose through the process of marking a reference
frame[21] with text or simple graphics,
where it was noted that by calculating
and matching homographies of the plane,
an illusory rigid planar patch appeared to hover upon objects
in the real-world, giving rise to a form of computer-mediated
reality which was described in[11].

In homographic modeling, a spouse may leave a virtual ``Post-it'' note
upon the entrance to a department
store
,
(Fig 6),

Figure 6:Recipient of the virtual ``Post-It'' note approaches
entrance to the grocery store and sees
the message through his ``smart sunglasses''.
Illusion of attachment (registration);
the virtual note appears to be truly attached to the ``Star
Market'' sign. (Thanks to Jeffrey Levine for
ongoing collaboration on this project.
)

or one might leave a grocery list on the refrigerator, that would
be destined for a particular individual (not everyone wearing the
special glasses
would see the message -- only those wearing the glasses and on the
list of intended recipients).

Note that the message is sent right away,
but ``lives'' dormant on the recipient's
WearComp until an image of the
desired planar surface ``wakes up'' the message, at which point it appears
in frames that lie within the same orbit of the projective group of
coordinate transformations in which it was placed.

When the incoming video falls into the orbit (as defined by the
projectivity + gain group of coordinate transformations[22])
of one of the templates, the comparison switches modes from comparing each
incoming frame with all of the templates to comparing each incoming frame
with just the one that has been identified as being in the orbit.

Personal imaging suggests that
the boundaries between seeing and viewing, and between remembering and
recording will blur.
Shared visual memory will begin to enlarge the scope of
what the visual memory currently provides,
for it may be possible to `remember' something or someone
that one never saw.

Personal imaging has evolved beyond
being a useful photographer's assistant, toward new
paradigms in cinematography, wearable tetherless
computer-mediated reality, and a graphical user interface on reality.

Special thanks is due to Rosalind Picard for suggesting that I write
this detailed historical account of my `personal imaging' efforts
and experiences, and to Steven Feiner for much help in getting it all
organized; both Picard and Feiner were instrumental in causing this
20 year effort to be come together in this document.
I'd also like to thank Hiroshi Ishii, Neil Gershenfeld, Sandy
Pentland, and Ted Adelson of MIT, as well as Chuck Carter
and Simon Haykin of McMaster University,
and many others, too numerous mention here, for various insightful discussions
germane to this work.
Thanks also to Thad Starner, Jeffrey Levine, Flavia Sparacino, and Ken Russell
for various collaborative efforts,
to Matt Reynolds (KB2ACE) for help in upgrading the
outbound ATV system, Steve Roberts (N4RVE) for much useful feedback
and suggestions, and to Kent Nickerson for help with much of the
earlier tone-decoders, radar systems, and the like.
Additional Thanks to
VirtualVision,
HP labs,
Compaq, Kopin, Colorlink,
Ed Gritz, Miyota, Chuck Carter, and Thought Technologies Limited
for lending or donating additional
equipment that made these experiments possible.
Finally, I thank my brother, Richard, for long and detailed
discussions from which the term `personal imaging',
and its general framework emerged.

Steve Mann.
Eudaemonic computing: Unobtrusive embodiments of `WearComp'
for everyday use.
In Proceedings of the First International Symposium on Wearable
Computing, Cambridge, MA, October 13-14 1997. IEEE.
/wearcomp/eudaemonic.html.

Steve Mann.
`VibraVest'/`ThinkTank': Existential technology of synthetic
synesthesia for the visually challenged.
In Proceedings of the Eight International Symposium on
Electronic Art, Chicago, September 22-27 1997. ISEA.

Author may now be reached at
University of Toronto,
Department of Electrical and
Computer Engineering, 10 King's College Road
Toronto, Ontario, CANADA, M5S 3G4,
mann@eecg.toronto.edu;
Project funded, in part, by the Council
for the Arts at MIT, by HP labs,
Palo Alto, and by BT, PLC.

More precisely, what is meant here is the
notion of self, from the perspective of the
individual, which defines a
physical boundary between the self
and the environment. This boundary
is called the `corporeal boundary' [2]
and is related to the concept
of ``prosthetic territory''[3].

The term ``cheating'' was not particularly appropriate
here, as there was an element of doubt surrounding
the morals and ethics of the casino establishments themselves.
Thus the Eudaemons were regarded by
many as heroes in a world of villains who might have killed or
``disappeared'' them had they discovered their methodology.

Because of the tedious nature of this procedure, many
assistants found this work boring. While the excitement of the project
drew in many first-time volunteer assistants, I had difficulty
finding assistants who would go on subsequent expeditions.

These were low-cost
units typically marketed as children's toys,
with a power output of
approximately 100 milliwatts, operating
in the 11 meter band), two attached to the body,
and two situated at the base station.

The author's work with Dr. Ghista of McMaster
University, which involved designing and building patient
monitoring hardware and software, was partially responsible
for much of the early inspiration in combining biological
sensing with wearable computing.
Later work during
a Biomedical Engineering course, which I took
from Dr. Hubert DeBruin of McMaster University,
and after that,
discussions with Prof. R.W. Picard,
and others when I arrived
at MIT, have further influenced my thinking
on wearable computing combined with biological sensing.

This early effort pointed toward a later effort of the
mid 1980s when I was to make an attempt at making wearable
computing fashionable, and be represented through
two modeling agencies. By 1985, I had established a
following in certain parts of the fashion industry.
However, after various fashion shows and the like,
I decided that function was more important than form,
and changed my focus from design back to art and science.

While there have been previous augmented reality
implementations of `Post-It' notes, the approach presented
here is novel in that it attains sub-pixel accuracy
through the use of the homographic
modeling/personal imaging approach.